SeaWorld San Diego trainer Robbin sheets feeds the killer whales at the end of a Shamu show rehearsal.
— John Gastaldo

SeaWorld has filed for an initial public stock offering that could fetch as much as $600 million for the theme park conglomerate owned by private equity firm The Blackstone Group.

Sea World Entertainment of Orlando submitted a prospectus Thursday to the U.S. Securities and Exchange Commission for its IPO. The company didn’t provide details yet about how many shares it proposes to sell, how much it expects to raise or when its shares would begin trading. Companies seeking to go public typically add these details in subsequent filings as the IPO date gets closer.

But industry experts say SeaWorld, which proposes to trade under the ticker symbol SEAS, is expected to raise $100 million to $600 million. A company spokesman declined to comment.

SeaWorld has chosen a good time to tap public markets, as the amusement industry wraps up a second year of recovery, say experts.

SeaWorld's Manta coaster attracted more than 1 million riders this summer.— Courtesy photo

“Theme parks had a good year after coming out of the economic doldrums,” said Dennis Spiegel, president of Cincinnati-based International Theme Park Services. “It began to turn around last year, and we saw the best year in 2012 that we’ve seen since 2006-2007.”

SeaWorld has performed better financially since Blackstone Group acquired the 11-park business from affiliates of Anheuser Busch in 2009 for $2.3 billion.

The company lost $57 million that year and $45 million in 2010. But by 2011, it had swung to a $19 million profit.

Through the first nine months of this year, the company’s earnings reached $86.2 million on total revenue of $1.1 billion, according to its IPO filing. It has hosted 24 million visitors at its SeaWorld, Busch Gardens, Aquatica, Discovery Cover and Sesame Place parks.

Besides San Diego and Orlando, SeaWorld Entertainment owns parks in Tampa, San Antonio, Williamsburg, Virg. and Langhorne, Penn. In November, it bought Knott’s Soak City in Chula Vista for $15 million. It expects to re-open the water park next year as Aquatica, boosting its San Diego footprint.

“They’ve been able to do well because they have not been shy about spending,” said Robert Niles, editor of Theme Park Insider. “This is a capital intensive business. You’ve got to spend money to make money. They’ve been rewarded for that, and they’re hoping the (financial) markets will reward them the same way their customers have.”

According to the prospectus, some of SeaWorld’s IPO proceeds would be used to pay off part of its $1.8 billion in debt. Blackstone also would receive payment in connection to an advisory agreement it has with SeaWorld. The rest of the money would be earmarked for general corporate purposes.

Some current shareholders are expected to offer their stock as part of the IPO. SeaWorld would not receive proceeds from these share sales.

“Blackstone is a private equity firm,” said Niles. “They’re in the business of spinning off their businesses, so it was inevitable there would be an IPO as some point so Blackstone could cash out.”

Niles added that Blackstone is only selling off a portion of its stake in SeaWorld. So even after the IPO, Blackstone would still control a majority of SeaWorld’s common shares.

That means it would retain voting power in matters such as election of the company’s board of directors and other corporate governance issues, according to the prospectus.